When you take pics in lower light conditions, you can encounter situations in which you have to up the iso, indeed. But you can compare this to a very silent passage in music, barely audible, and when you up the volume of your amplifier, you hear it better but you get a lot of noise and hiss from the ampli with it. The better your ampli, the less problems you have.

Same goes for camera's. You'll always meet some  "no tresspassing" sign somewhere where your camera is at its maximum performance. Beyond that, you get noise.

There is software to reduce it, but that usually goes at the expense of a bit of sharpness.
I personally also never use any settings on the camera to sharpen, enhance etc as it's never as good as when done afterwards.

So, for sharper pics:
-see that you have more light

• use a tripod
• lean against a wall, or find some support to limit body trembling (heartbeat, muscle tension etc)
• experiment what your camera can do and what not. and be creative withibn the limitations.
• eventually use a flash. I never do, but that's personal.

There are no Borg. All resistance is fertile.